The present invention pertains to the acoustic art and, more particularly, to an improved loudspeaker enclosure.
Ideally, a loudspeaker system should transduce electrical signals provided by a power amplifier into a proportionate level acoustical output, of the same frequency, across the entire audio bandwidth.
In practice, however, conventional loudspeaker systems fail, particularly at low frequencies, to faithfully reproduce the electrical input. The nature of this failing is apparent upon analysis of a typical loudspeaker system. The modern speaker system is normally comprised of a box to the front side of which is mounted one or more speaker drivers. The box is normally a rigid structure made of a heavy, dense material such as metal, plywood or particle board. Great care is taken to make sure that no undesirable air leaks exist, and acoustical dampening "fill" materials are often used. The basic purpose of such an enclosure is to totally absorb backwave radiation from the speaker which would otherwise tend to cancel the desired frontwave radiation.
The basic problem with conventional speaker systems is that they develop one or more dominant low frequency resonances. These resonances result from the spring action of the air in the enclosure enforcing excursions of the driver at defined frequencies. The result is a "boominess" from the speaker system at the resonant frequencies and coloration of other frequencies.
Most of the research into refining the operating characteristics of such systems has been the tuning of the system to realize a desired compromise. To this end, tuned ports have been added to the enclosure; the volume of the enclosure has been adjusted in accordance with operating parameters of the driver; the electrical signal to the speaker has been equilized, and so forth.
While these refinements have improved the sound qualities of conventional loudspeaker systems, there yet exists in this art a long felt need for a high resolution system design, particularly at bass frequencies.